Device for traversing a flexible linear product for spooling

ABSTRACT

A linear traverse mechanism for guiding the spooling of a flexible linear product at high speed, made possible by reducing the inertial load of the mechanism while reducing the angular deflection of the filament. The mechanism includes a pivotally mounted guide arm controlled by an electric motor having precision indexing ratio characteristics to compensate for linear error. In one embodiment, the linear product is fed through a guiding means carried by said traverse arm to be discharged adjacent a receiving spool.

RELATED INVENTION

[0001] This application is a continuation-in-part of my copending application, Ser. No. 09/427,443 filed Oct. 27, 1999.

BACKGROUND OF THE INVENTION

[0002] This invention relates generally to the field of spooling a flexible linear product such as thread, wire, cable, hose, and the like, and more particularly to an improved guiding means which moves in a plane parallel to that of the spool which forms progressive layers of product as the spool coil rotates, while minimizing tension fluctuation that typically accompanies high speed traversing.

[0003] Traverse guiding means are well known in the art, and have included a pivotally mounted guide having an orificed free end through which the product passes, as well as mechanical driving means, including a driven disc, and linkage communicating with a point on the guide.

DESCRIPTION OF THE PRIOR ART

[0004] Previous pendulum type devices have been employed to move a flexible product in a linear motion while the product is being wound onto a package, such as a spool or coil. Some of these mechanisms have not been concerned with linear motion synchronized with the rotation of the winding members. Others, include a mechanical cam device to compensate for the non-linear motion of the guide. These mechanical linkages add considerable inertia to the device, thereby slowing the spooling process. Previous devices have not performed direction reversal of the pivotally mounted guide, other than end of stroke mechanical linkage adjustments. Where the guide is driven at high speeds, the heavy inertial load of the mechanisms prevents any instant reversal of the path of movement. Previous means of reversal have included mechanical cams, slides, complicated mechanical linkages, and gears of both arcuate and oval configuration. Previous traversing components, for the most part, have not addressed the tension fluctuations that is common to traversing.

SUMMARY OF THE INVENTION

[0005] Briefly stated, the invention contemplates an improved guiding means by which a continuous segment of the product is moved in a plan parallel to the axis of the spool or core of the winding device, while reducing the inertial load of the traversing mechanism and minimizing the angular deflection of the product, thereby increasing the speed by which the product can be traversed in a precise manner. It is an object of the invention to electronically interface the motion of the traversing guide with the winding member, so that the positioning of traverse motion may be programmed for required traverse profiles and reversals of the guide. Thus, it is possible to utilize less than the entire arcuate path of motion of the free end of the guide, where use of the entire path is not required, whereby the same mechanism may be employed for winding spools or cores of varying axial length.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is a perspective view showing the process by which the product is layered onto a rotating arbor or spool, and the relationship of the guiding mechanism to the rotating member.

[0007]FIG. 2 is a front view in elevation showing a traversing mechanism forming a part of an embodiment of the invention.

[0008]FIG. 2a is a side view in elevation thereof.

[0009]FIG. 3 is a block diagram showing the components used to synchronize the traverse assembly to a winding member.

[0010]FIG. 4 is a schematic drawing showing longitudinal motion of a traverse assembly as a function of 0 and radius.

[0011]FIG. 5 is a program flow of a logic controller.

[0012]FIG. 6 is a program flow of a traverse motor controller.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENT

[0013] Referring to FIG. 1 in the drawing, there is illustrated a longitudinally mounted guide (1), an orificed free end of which moves in a plane parallel to a winding surface (2) following the speed of a winding apparatus (3) to a set ratio to result in layering of the wound product.

[0014] If the ratio of the guide (1) to the winding apparatus (3) is changed, the space between the layering may be increased or decreased at will. If the reversal at the end of the longitudinal stroke is changed, the layer width (4) may be increased or decreased as required.

[0015] One problem that exists is in the movement of the guide (1). The mechanism required to move the guide to and fro, at a speed following the winding apparatus, and to perform quick reversals of direction at the end of a stroke, is that of high inertia. A secondary disadvantage of this configuration is at high speed, the motion of the guide in its path causes tension fluctuations in the product due to the deviation of the guide from an aligned position.

[0016] Referring to FIG. 2, when the arm (8) and product guide (9) are attached at a pivot (7) and allowed to swing about this pivot in an arc (10) that is parallel to the winding plane (11), the inertia of the assembly is significantly reduced. By driving the pivotally mounted guide from a driven rotating member (5), the rotational reversal of the member can be used to limit the stroke of the guide. The flexible product is fed through entry hole (12) around sheave (13) through produce guide (9) to rotating arbor (14). Rotating member (5) converts rotary motion to linear motion through arm (6). this causes the entire assembly to oscillate around pivot (7). Due to the product path through the axis of the mechanism, tension fluctuations are greatly reduced that are caused by the side to side motion of longitudinal traversing. The produce guide (9) is so constructed as to guide the product only in the desired parallel winding plans. As the product leaves the sheave (13) it is free to form a natural angle to the varying diameter of the core. This path eliminates sharp bends that are detrimental to many filament products. The ultimate goal of the invention is to position the filament guide (9) in the precise desired location along the winding plane (11) with respect to the rotational position of the winding arbor (14).

[0017]FIG. 3 schematically illustrates the disclosed embodiment. Shaft member (15) is driven by either a constant or variable velocity motor (16) which may be manually controlled by a separate speed controller. Element (17) is a feedback encoder device driven from shaft (15) which sends a digital position signal to a controller (18). Controller (18) is a logic controller which contains the necessary logic for the synchronization of the two drives and interface from the operator input. Component (19) is the controller that commands the traverse motor (20) to the desired position for accurate positioning. The rotary position of the traverse is communicated to the drive controller (19) by encoder (22).

[0018] Operator interface is accomplished by means of a process control device (21) with the capabilities of setting selectively any of a plurality of ratio and position criteria.

[0019] Prior to the start of the winding cycle, a “homing” routine is initiated. This routine rotates the traverse drive motor (20) in the counter-clockwise rotation until switch (24) is activated. This switch is positioned to activate when the traverse arm (23) is at right angle to the winding axis. At this point the origin of the traverse arm is set.

[0020] With reference to FIG. 4, encoder (22) is a bi-directional device that is configured to add or subtract pulses dependant on the direction of rotation. CCW rotation adds, CW rotation subtracts. This numeric value is directed to the traverse motor controller (19) for positioning. In order to calculate the angular value of the encoder with reference to the linear position along plane (P), the equation $t = {a\quad \tan \quad \left( \frac{Y}{\sqrt{r^{2} - Y^{2}}} \right)\quad {is}\quad {{used}.}}$

[0021] Where:

[0022] t=angle of the arm from the origin in radians

[0023] r=radius of the arm in inches

[0024] Y=any linear point on the (P) plane measured from the origin (0).

[0025] In order to calculate the numeric value of the encoder with reference to any linear position, the equation ${Da} = {a\quad \tan \quad \left( \frac{Y}{\sqrt{r^{2} - Y^{2}}} \right)\quad \left( \frac{Tp}{2\pi} \right)\quad {is}\quad {{used}.}}$

[0026] Where Da=the numeric value of the traverse encoder (10) position. Tp=encoder steps per revolution (PPR) of the traverse encoder (10). 2 is the value of radians for one rev (360°).

[0027] Any position along the (P) plane may now be converted to a numeric value of the traverse encoder (10). In order to simplify the calculations of the processor, a function statement is declared: ${{Da}(y)} = {{arc}\quad \tan \quad \left( \frac{Y}{\sqrt{r^{2} - Y^{2}}} \right) \times \left( \frac{Tp}{2\pi} \right)}$

[0028] Any value of Da may now be found by inserting the linear position (Y) into this statement.

[0029] (Fsi) is the end of the desired forward motion, measured in inches from origin and is derived from the equation Fsi=Rsi+Tw. (Rsi) is the end of the desired backward motion, measured in inches from origin. Tw represents the total traverse width in inches. (RSI is a negative quantity).

[0030] In order to create a symmetrical package and for operator ease it is required that the beginning of the layer start at point (Fsi) and end at (Rsi). (Rsi) is a constant that is manually measured from origin and entered into the processor in inches. The processor then evaluates the numeric address of the (Rsi) by placing (Rsi) for Y in the above formula. Tw is the desired traverse width in inches entered by the operator before the process is started. (Fsi) is derived by the processor by adding TW to (Rsi). I (lay) is the value of the desired lead of the filament and is expressed in inches per revolution of the winder member. This value is entered by the operator on setup.

[0031] In order to calculate the rotational position of the winding arbor (15) in revolutions or part thereof, the output of the winding arbor encoder (17) is directed to an accumulative counter (C1). This counter is set to zero during the homing routine and at the end of each traverse stroke. It accumulates counts as the process proceeds. The rotational value is derived by Cs the equation ${Cr} = \frac{Cs}{Cp}$

[0032] where Cr=revolutions of the winding arbor (15). Cs=the total accumulated count of the counter C1 and CP=pulses per revolution of the winding encoder (22).

[0033] As the process starts, the position of the traverse is at (Fsi). The logic continuously commands the motor 20 to a position that satisfies the equation Y=Fsi−(L*Cr), that is, the linear position is the front stop in inches−(lay*arbor revolutions).

EXAMPLE

[0034] Let:

[0035] Rsi=−4 Tw=8 L=0.2 Cs=640 Cp=480 Tp=1800 r=10.75 ${Cr} = {{\frac{Cs}{Cp}\quad {Cr}} = 1.333}$

[0036] Fsi=Tw+Rsi Fsi=4 ${{Da}(Y)} = {a\quad \tan \quad \left( \frac{Y}{\sqrt{r^{2} - Y^{2}}} \right)\quad \left( \frac{Tp}{2\pi} \right)}$

[0037] Y=Fsi−(L×Cr) Y=3.733

[0038] Da(Y)=101.607

[0039] If the rear stop (Rsi) is entered as −4 inches and the traverse width is 8 inches, the front stop (Fsi) position is calculated as 4 inches.

[0040] If the winding arbor count (Cs) is 640 steps and the arbor encoder PPR is 480, the arbor revolution count (Cr) is 1.333.

[0041] The desired traverse motion from the front stop is (Cr*L)=0.267 inches. This value (Y) is 3.733 inches from the origin.

[0042] When the traverse reaches the rear stop position, the logic commands the motor to a position that satisfies the equation Y=Rsi+(L*Cr), that is, the linear position is the rear stop in inches+(lay*arbor revs).

[0043] When the traverse reaches (Rsi) the accumulative count of (C1) is set to zero, the rotation of the traverse motor is reversed, and the equation Dti=Rsi+(L*Cr) is applied. This process continues, alternating between the two calculated values, as subsequent layers of filament are wound.

[0044] The process of layer winding requires that, when the filament reaches the end of the traverse stroke at either (Rsi) or (Fsi), lateral motion must cease for a partial rotation of the winding arbor. This is achieved by applying a second counter that also receives a count from encoder (17). When (Rss) or (Fss) is reached, this counter holds the accumulated value of C1) at 0 for the period of the preset count entered through setup. This negates Cr for a period which in effect holds the traverse motion during this period. This process will be made clear later in the process.

Sequence of Operation

[0045] Legend: Ce Winding arbor encoder Cp Pulses Per Revolution (PPR) of the Winding Arbor Cs Accumulated Count of the Winding Arbor Dir Direction of Traverse Motor Dti Desired Traverse position along Winding Plane in Inches Dts Desired Rotational Traverse position in Encoder Steps Fsi Front Stop in Inches Fss Front Stop in Numeric Value HS Homing Switch L Traverse Lead (Lay) Rsi Rear Stop in Inches Rss Rear Stop Numeric Value Run Run Signal Te Traverse Encoder Tp Pulses Per Revolution (PPR) of the Traverse Arm Tw Traverse Width

[0046]FIG. 5 shows the program flow of the logic controller, (30),(31), and (32). The values are entered by the operator, to set the values of L(Lay), Tw (Traverse width). Rsi (Rear stop in inches). These values are stored in calculations of Fsi and Dti (39), a discrete input to start or stop the run sequence. The logic of the run trigger is well within the skill of one skilled in the winding art. Neither is it necessary to specify in detail the type of switches, encoders, etc. as this is also within the capabilities of one skilled in the art.

[0047] (34) is the digital signal from the winding arbor that is passed through internal relay Y1 to either accumulative counters C1 or C2 (Acc). (C1) is an accumulating counter that stores the value of Cs which is conveyed to math block (37). This counter is reset by logic that will be described in subsequent steps. The function of counter (C2) is to accumulate counts from the winding arbor in place of C1 to allow for lead dwell at the end of each traverse stroke. The preset (Pre) value is set in the operator's interface. When the accumulated value (Acc) teaches the (Pre) value, the done bit (Dn) is set, Y1 is unlatched and the (Acc) value of C2 is reset to 0. By redirecting the count to C2, the value of Cr is not increased, thereby causing a dwell in the traverse stroke until C2 is reset. When Y1 is unlatched, the count from the encoder (34) is redirected C1. (33) is a math block that determines the value of Fsi. (37) is a math block that determines the value of Cr. The latching of (Y1) will become apparent in subsequent steps.

[0048] The sequence of operation starts with step (43). On startup and at the end of each cycle, a “homing routing (43) is instituted in the processor and a discrete signal is sent to the motor controller “MC”. The processor waits for a “homing complete” signal to be received from the MC (44) before allowing the run sequence to be initiated. Once the “homing complete” signal is received, the run sequence (45) can be initiated. When the run sequence is established, the winding arbor is started (46) and continues to rotate until the run signal is removed. During the cycle, math block (37) is continuously calculating the rotation of the winding arbor by dividing the accumulated count of the arbor encoder (34) by the steps per rev (Cp) The result, (Cr) is a varying value of the revolutions of the arbor. The value is directed to the MC through the com bus (47). The accumulated count of (C1) is reset to 0 by the internal relay (Y1) at the end of each traverse stroke. The values of (30), (31) and (32) are entered before start through the operator's interface and conveyed to the processor through the data bus. (30) is the value of L (traverse lead per revolution). (31) is the value of the desired traverse width (Tw). (32) is the entered value of the rear stop in inches (Rsi). This value is used by the MC to calculate the point of traverse reversal in its Cw rotation and is also conveyed to math block (33). The value of the front stop in inches (Fsi) is derived from math block (33) by subtracting Rsi from Tw. This value is routed to the MC data bus (47).

[0049] The Motor controller logic can be seen by referring to FIG. 6. Item (50) is the communication data bus between the logic processor “LP” and the MC. (51) is the evaluation block for the function call described above. The value of r is a constant that is equal to the length of the traverse arm. (Tp) is the value of (Te) PPR. (52) is a math block that ascertains the numeric position of the traverse encoder (Te), relative to the linear position of the front stop (Fsi). (53) is a math block that ascertains the numeric position of (Te) the traverse encoder, relative to the linear position of the rear stop (Rsi). (54) is a count in revolutions of the winding arbor from the LP (55) is a discrete input from the home switch signifying that the traverse arm is at the origin position. The numeric position of the traverse arm is derived in block (56) that sums the steps from encoder (57), which is attached to the pivot of the traverse arm.

[0050] When the LP initiates a “homing routine” (58), block (59) initiates a CCW rotation to the motor. This motion continues until Hs is closed, the motor is command to stop motion (61) and the position of the (Te) is set to zero. This establishes the origin position of the traverse. This origin places the traverse arm at a right angle to the winding plane. The processor then commands the motor to rotate until the numeric value of the encoder is equal to the value of (Fss). The arm is now placed at the precise position of the front stop and the homing routine is complete. Block (64) signifies that the “homing routine” is complete after motion has ceased.

[0051] When the run command is received from the LP, block (65 sets the motor to the CW rotation. Math block (66) sets the value of Y to equal Fsi−(L*Cr). In doing so, block (67) commands the motor to move to the numeric position of the function block as a function of Y. As the arbor count increases, Y is incrementally decreased from the front stop (Fsi) by the value of (L). This process continues until the position of the arm reaches the numeric value of the rear stop (Rss). When block (68) is evaluated as true:

[0052] (Y1) is latched resetting the value of (Cr) to zero,

[0053] Block (69) reverses the rotation of the motor.

[0054] The value of (Y) is recalculated in block (70) to equal Rsi+(L*Cr). In doing so, block (71) commands the motor to move to the numeric position of the function block as a function of Y. As the arbor count increases, Y is incrementally increased from the rear stop (Rsi)by the value of (L). This process continues until the position of the arm reaches the numeric value of the front stop (Fss). When the block (72) is evaluated as true: (Y1) is once again latched, resetting the value of (Cr) to zero. The processor loops back to block (65) starting the process over again. This loop continues until the run sequence is interrupted by the LP.

[0055] It appears that this incremental motion of the traverse might cause the arm to pulse to its commanded position, but this stepping motion is dampened by acceleration/deceleration settings in the motor controller.

[0056] I wish it to be understood that I do not consider the invention to be limited to the precise details of structure shown and described in the specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.

[0057] I claim: 

1. In a device for traversing a linear flexible product for winding upon a spool or core, said device including a pivotally mounted traverse arm, a rotating motor, and a link interconnecting a point on a rotating part of said motor with a point on said traverse arm for imparting arcuate motion thereto over a predetermined arcuate path, the improvement comprising: means for controlling rotation of said motor through arcuate sectors of 180 degrees and less, such that a free end of said traverse arm moves at a substantially uniform rate of traverse over said predetermined path.
 2. The improvement set forth in claim 1 , in which said means comprises: motor means for driving said spool at predetermined uniform angular velocity, an electronic controller feedback means driven by rotation of said spool for generating and feeding a reference signal to said controller, said controller including a ratio block for determining the ratio between said motor means and said rotating motor; and a process control device for selecting ratio and position criteria, and communicating said criteria to said controller.
 3. The improvement set forth in claim 2 , in which said process control device is manually adjusted.
 4. The improvement set forth in claim 1 , in which the linear flexible product is fed coaxially with respect to a pivot axis of said traverse arm, and parallel to said arm to be discharged from said arm adjacent a free end of said traverse arm.
 5. The improvement in accordance with claim 4 , said traverse arm including tubular guiding means adjacent said free end thereof.
 6. In a device for traversing a linear flexible product for winding upon a spool or core, said device including a pivotally mounted traverse arm, a rotating motor, and a link interconnecting a rotating part of said motor with a point on said traverse arm, the improvement comprising means on said arm for receiving said product along a path of motion substantially coaxial with respect to a pivot axis of said arm, and guiding means on said arm for guiding said product to a point of discharge adjacent said spool. 